Iirc, A8 is using OpenAL, so I would be a little bit surprised if this method would still work. But yeah, otherwise it seems like you just have to provide PCM packages? So, grab the bitrate, depth and the packages and skim forward until you are at your point of interest. The math is well described on the internet.
I really need to do this soon
That's nice, but it doesn't mean that we need to write code for you. If you need something urgently, pay someone for it. Or wait like everyone else until someone has the time and enthusiasm to write code for you for free